Sharif Digital Repository

In 2009, a general equation of state (EOS-III) based on an effective near-neighbor pair interaction of an extended Lennard-Jones (3, 6, 12) type has been introduced as : , where is the compressibility factor, p and ρ stand for pressure and molar density , respectively, T is Temperature , and e, f and g are the temperature dependent coefficient of the equation of state . the Z_th and Z_in are the thermal and internal contributions of pressure in the compressibility factor, respectively. this equation of state gives a good description of all types of nano- and bulk –solid and bulk fluid at entire temperature and pressure ranges for which thee is experimental data. Investigation show that... 

The importance of creating a fluid flow with accurate and controllable flow in many industries is undeniable. There are several ways to create this type of flow, and a variety of pumps can be used to create such a flow. The presence of noise, limitations in reducing the flow rate (sometimes in some pumps the flow rate can not be reduced to a minimum), depreciation costs and many other limitations, reduce the attractiveness of using conventional pumps in some applications. The subject of this project is the design and construction of piezoelectric based micro-pumps to solve the above problems. In many applications, the need for fluid flow with very low flow and high quality and accuracy is... 

The rise in carbon dioxide levels has led to the manifestation of numerous environmental challenges. Currently, the absorption and conversion of carbon dioxide into valuable fuel resources such as synthetic gas, methane, and ethylene are deemed crucial from both environmental and economic standpoints. Despite the presentation of photocatalysts such as titanium oxide and electrocatalysts such as copper, silver, and zinc, their efficiency in CO2 conversion is found to be insufficient. One potential solution to this problem is the utilization of photoelectrocatalytic CO2 recovery. In this study, the aim was to enhance the photoelectrocatalytic reduction of CO2 by designing and manufacturing... 

Nowadays diversion of products from authorized distribution channels to the gray markets has been considered by manufacturers. There many cases that the products of main industries are supplied through gray markets. Gray markets are divided into two categories. The first category is parallel imports where an unauthorized distributor or a third party imports the products from a low price market into a market with high price. In most researches of parallel importation it is assumed that a monopoly manufacturer distributes its products in both two markets. In the second category of parallel importation researches, it is assumed that the manufacturer distributes the products in a certain market... 

Considering the importance of environmental issues and the limitation of fuel supplies in the world, car issues have become one of the most important debates of the day. The methods used to reduce fuel consumption and emissions of greenhouse gases are primarily aimed at changing vehicle structure to reduce drag. An external body shape has been developed to reduce drag forces over the years. Due to the existence of limitations in the actual conditions of the theory, such as the beauty and convenience production, other methods should be examined. In this study, the structure of superhydrophobic properties materials with the emphasis on innovation has been considered. In order to investigate... 

Biological layers are one of the main problems related to water transfer with pipe lines which are formed through time in the inner surface of the pipes by the water nutrients. Hence, the inner surfaces in the pipe lines and water refineries should be made in order not to let these biological layers to be made. The reason is that when the biofilm is formed on these surfaces, the traversing water is polluted. Dredging of these pipes is not only necessary in most of the countries in the world and needs huge amounts of water but is also very complex and expensive.In this research, nanomaterials, namely ZnO, T〖iO〗_2،S〖iO〗_2 have been used to cover the surface of concrete and steel pipes (The... 

Preformed particle gels (PPGs) due to its advatantage over commonly used in situ gels has been successfully applied for controlling excess water production in mature oil reservoirs. Field results of using PPGs in oil fields shows that commonly used PPGs are highly sensitive to hard reservoir conditions such as high temperature and salinity and can not effectively block fractures and high permeability layers.Objects of this study are synthesis and evaluating performance of this novel polymer based hydrogel in oil reservoirs with high temperature and salinity. Central composite design ( which is a experiment design approach) was used for synthesizing thirteen gel samples and optimal sample was... 

Sand production from oil reservoirs leads to various problems, such as well productivity reduction, operating equipment corrosion, and increased production costs. Therefore, controlling sand production in unconsolidated reservoirs is crucial for operating companies. Chemical injection into the formation in order to strengthen and reduce sand production is one of the most important methods of sand control. In this study, a hydrogel nanocomposite was designed and its effectiveness in sand control was investigated. Various tests were carried out to define and assess its efficacy, as follows: Morphological tests demonstrated the creation of a dense, homogeneous, and porous structure. Structural...